Drucella Andersen
Headquarters, Washington, D.C.
April 24, 1992
(Phone: 202/453-8613)
Don Haley
Ames-Dryden Flight Research Facility, Edwards, Calif.
(Phone: 805/258-3456)
RELEASE: 92-52
X-31 DEMONSTRATOR FLIGHTS RESUMED AT AMES-DRYDEN
Flights of the X-31 Enhanced Fighter Maneuverability
demonstrator aircraft resumed yesterday afternoon at NASA's
Ames-Dryden Flight Research Facility, Edwards, Calif.
Today's mission, piloted by Carl Lang of the German firm
Messerschmitt-Bolkow-Blohm, lasted about 1 hour. It was a
check of aircraft systems after a period of planned
maintenance. The X-31s are being flown at Ames-Dryden to show
the value of thrust vectoring (directing engine exhaust flow)
coupled with an advanced flight control system for close-in air
combat at very high angles-of-attack.
An international test organization, managed by the Defense
Advanced Research Projects Agency (DARPA), is conducting the
flight tests to obtain data that may apply to
highly-maneuverable next-generation fighters.
During the next year, an international team of pilots will
make as many as 20 test flights a month with each X-31. They
will expand the plane's flight envelop at Ames-Dryden to
prepare for military utility evaluations at the Naval Air Test
Center, Patuxent River, Md., in early 1993.
The two aircraft made 108 test flights in the program's
initial phase of operations at Rockwell International's
Palmdale, California's facility before resuming operations at
Ames-Dryden. The X-31 first flew in October l990.
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"Angle-of-attack" is an engineering term for the angle of an
aircraft's body and wings relative to its actual flight path.
In combat maneuvers, pilots often fly at extreme nose-high
angles while the plane continues to go forward. At high
angles-of-attack, forces produced by the aerodynamic surfaces
are reduced and the pilot can lose control of the aircraft.
Thrust vectoring paddles on the X-31's exhaust nozzle direct
the exhaust flow to provide control in pitch (up and down) and
yaw (right and left) that improves maneuverability at high
angles-of-attack. Military officials believe that this can
give fighter pilots a tactical advantage over planes without
enhanced controls.
Besides DARPA and NASA, the X-31 International Test
Organization (ITO) includes the U.S. Navy, the U.S. Air Force,
Rockwell International, the Federal Republic of Germany and
Messerschmitt-Bolkow-Blohm. About 110 people from the ITO
agencies are assigned to the program. NASA is responsible for
flight test operations and will take part in aircraft
maintenance and research engineering.
The X-31 is the first international experimental aircraft
development program administered by a U.S. government agency.
It is a key effort of the NATO Cooperative Research and
Development Program.
-end-
NOTE TO EDITORS: Photographs are available to media
representatives to illustrate this release by calling
202/453-8375.
Color: 92-HC-249 B&W: 92-H-285
92-HC-250 B&W: 92-H-286